This invention relates generally to disposable, single-use lancet assemblies and methods, a lancet assembly being used for percutaneous entry into a body segment, such as pricking a finger to collect a small blood sample. More specifically, this invention relates to lancet assemblies which are totally self-contained and packaged as presterilized devices and which require but one operational step to ready a device for use and for performing a lancing operation.
Contemporary wide, high volume use of lancets to acquire blood samples from fingers and other body donor sites has resulted in conceptualization, design and development of a large variety of single-use lancet assemblies. Historically, commercial viability of lancets is based upon device cost, device safety, device efficacy (effectiveness of achieving desired blood volume from a patient sample) and level of pain of lancing. As an example, the earliest and likely lowest cost lancet was made from a simple sharpened blade by which a lancing procedure was manually administered by a medical attendant or self-administered by a patient. Even though a sizeable number of such lancets are still being used, considerations of safety (e.g. potential of inadvertent sticks by previously used and contaminated lancets) and associated pain levels have resulted in displacement of simpler, low-cost blades with safer, single-use devices, and especially those which are generally considered to be less painful.
Even so, lancet and associated lancing costs have remained important product selection factors. From a broad view, lancing cost includes far more than cost of the lancet, itself (although lancet cost must be considered as a primary selection criteria). Other costs which are important, especially in the hospital, clinic, doctor""s office and other like places where medicine is practiced, are associated with convenience or ease of use and numbers of residual parts which must be gathered up and disposed of at the end of each procedure. While such factors may seem insignificant, lancets which require, for example, protection by a blister pack have commonly been displaced by devices which do not require additional packaging.
One of the common methods for eliminating the need for external packaging has been development of removable sterile covers which protect just the lancing blade and are easily removed immediately before lancet use. Such a method is disclosed in U.S. Pat. No. 5,755,733 issued May 26, 1998 to Susumu Morita (Morita). Morita discloses a lancet blade which is over-molded with a removable sterile covering. In this manner, a blade, once sterilized, remains uncontaminated until the covering is removed. However, even the device disclosed by Morita requires an operational step to remove the covering prior to use and, then, disposal of the small covering, which may prove to be hazardous if inadvertently left in such places as children""s and pediatric units, after a procedure.
In brief summary, this novel invention alleviates all of the known problems related to providing a true single-step, disposable lancet. Lancet devices made according to the instant invention comprise a housing and a lancet blade, which may be of a blade or pin format or any other form which yields acceptable amounts of blood flow. Such a device also comprises an energy storing member which is preferably kept in a relaxed state for transport and storage prior to use, although the state of the energy storing member is not an essential part of the invention.
Lancets made according to this invention are true single-step lancets whereby the entire lancing procedure involves but a single operational step. For example, there is no external package or blade cover which requires an additional step to remove a lancet blade covering. The single step operation lancet is accomplished without degrading or comprising device sterility, and lancet actuation is accomplished by a single unidirectional motion. Such motion separates the lancet blade from a protective cover and actuates the lancet. If the energy storing member is kept in a relaxed state prior to actuation, energy which is stored to drive the lancet blade is supplied by the same unidirectional motion.
In a preferred embodiment of the instant invention disclosed herein, an orifice through which a lancet blade passes to lance is substantially blocked prior to device actuation and cleared by displacing an orifice covering or blocking apparatus during actuation to assure creation of an unobstructed (clean) pathway for the blade. Preferably, the sterility maintaining cover, disposed about the blade prior to actuation, is displaced relative to the blade and separated from the blade in preparation for firing, in such a manner as, to sweep undesirable contaminants from the pathway of the blade.
In all embodiments, such devices are fabricated using a housing, an energy storing member, to which is generally affixed a lancet blade, and an actuator, the actuator being displaceable in a single direction relative to the housing.
Accordingly, it is a primary object to provide a self-contained lancet which requires but one operational step to perform a lancing procedure, the lancet comprising:
a housing comprising an elongated contiguous side wall which surrounds and shelters lancet parts residing within the housing, the housing further comprising an open first end wherethrough an actuator is unidirectionally displaced to energize and activate a lancing cycle and a slot on the other end through which a lancet blade is displaced;
the lancet blade, disposed within the housing for transport before use and for disposal after use;
a lancet blade covering, removable by action of the single operational step, being disposed within the housing to provide a sterile encasement about the lancet blade before use, the covering maintaining the lancet blade in an uncontaminated state until the lancet is uncovered therefrom;
the actuator which is displaceable from a first state, whereat digital access is provided, toward and to a second state whereby the lancet is activated;
an energy storing member which communicates with the actuator at a first site and is securely affixed to the lancet blade at a second site and which stores energy during a first portion of actuator displacement from the first state to the second state and is released during a second portion of actuator displacement from the first state to the second state to discharge the lancet outward from the housing and then to return the lancet to protective safety of the housing; and
apparatus which assures separation of the lancet blade from the removable covering during the first portion of displacement of the actuator.
It is a further object to provide a self-contained lancet having apparatus for clearing undesirable material from the region of the slot within the housing to clear an unobstructed pathway for the lancet blade.
It is an object to provide a method for using a self-contained lancet which requires but one operational step to perform a lancing procedure, comprising the steps of:
providing the self-contained lancet comprising:
a housing comprising an elongated contiguous side wall which surrounds and shelters lancet parts residing within the housing, the housing further comprising an open first end wherethrough an actuator is unidirectionally displaced to energize and activate a lancing cycle and a slot on the other end through which a lancet blade is displaced;
the lancet blade, disposed for transport before use and for disposal after use, within the housing;
a covering, removable by action of the single operational step, disposed within the housing to provide a sterile encasement about the lancet blade before use, the covering maintaining the lancet blade in an uncontaminated state until the lancet is separated therefrom;
the actuator which is displaceable from a first state whereat digital access is provided toward and to a second state whereby the lancet is activated;
an energy storing member which communicates with the actuator at a first site and is securely affixed to the lancet blade at a second site and which stores energy during a first portion of actuator displacement from the first state to the second state and is released during a second portion of displacement from the first state to the second state to discharge the lancet outward from the housing and then to return the lancet to protective safety of the housing; and
apparatus which assures separation of the lancet blade from the removable covering during the first portion of actuator displacement;
displacing the actuator unidirectionally from the first state to the second state thereby in seriatim storing energy in the energy storing member and separating the lancet blade from the removable covering during the first portion of actuator displacement from the first state to the second state and then releasing the energy storing member at the end of the second state of actuator displacement thereby permitting energy stored in the energy storing member to discharge the lancet from the housing and return the lancet into the housing.
It is a further object to provide a method for using a self-contained lancet which comprises additional steps of providing apparatus for clearing undesirable material within the housing from the region of the slot to clear an unobstructed pathway for the lancet blade and sweeping or otherwise clearing unwanted material from the region of the slot during the first portion of displacement of the actuator from the first state to the second state.
These and other objects and features of the present invention will be apparent from the detailed description taken with reference to accompanying drawings.